The Nato summit has opened at the Celtic Manor with leaders from across the world gathering to debate pressing security issues including Afghanistan, Ukraine and Iraq.

World leaders have been arriving at the hotel in Newport throughout the morning, where they were greeted by First Minister Carwyn Jones, Welsh secretary Stephen Crabb and Newport council leader Bob Bright.

US President Barack Obama arrived at the hotel by helicopter on Wednesday night after flying in from Estonia on board Air Force One, while other leaders - including German chancellor Angela Merkel, who touched down at Cardiff Airport at 10am - arrived this morning.

This morning, David Cameron joined the President on a visit to Mount Pleasant Primary School in Newport, while other ministers and officials visited other schools before the conference formally started at around 11.45am.

He outlined that the Western alliance of 28 countries faces dramatic changes in the world - accusing Russia of attacking Ukraine and saying that the South will see violence, insecurity and instability.

“We will take important steps,” he said, “to counter these threats and to strengthen the defence of our allies.”

Two of the big issues on the table at the summit - the conflict in Afghanistan, and the situation between Russia and Ukraine - will be dealt with in sessions between world leaders being held on Thursday.

Islamic State and events in Syria and Iraq are set to be the main topic discussed over dinner when the heads of state and government meet at Cardiff on Thursday for a working dinner, with the situation in Ukraine also likely to be discussed.

Earlier in the day David Cameron told the BBC he wouldn’t rule anything out over Islamic State, which has over-run a large swathe of Syria and Iraq.

He said that any military action must not be Western Intervention over the heads of neighbouring states.

While world leaders are meeting demonstrations are expected in Newport this afternoon with protesters gathering at noon at the city’s Cenotaph.

The protesters are marching towards the Celtic Manor site where they are hoping to hand over postcards collected during their ramble across Wales, dubbed the Long March to Newport.

At 6pm two protests are expected to take place within Cardiff city centre.

The Stop the War Coalition is aiming to gather and march down key shopping strip Queen Street towards Cardiff Castle.

At the same time, the Anarchist Action Network is calling for a “mass action to besiege Cardiff Castle”. They want to get as close to the site as they can, wearing black in solidarity with what they describe as the victims of Nato attacks and clad in masks to protect themselves against police surveillance.

WalesOnline is part of Media Wales, publisher of the Western Mail, South Wales Echo, Wales on Sunday and the seven Celtic weekly titles, offering you unique access to our audience across Wales online and in print.